To send the message to the recipient securely, authenticated encryption schemes were proposed. In 2008, Wu et al. [T.S. Wu, C.L. Hsu, K.Y. Tsai, H.Y. Lin, T.C. Wu, Convertible multi-authenticated encryption scheme, Information Sciences 178 (1) 256–263.] first proposed a convertible multi-authenticated encryption scheme based on discrete logarithms. However, the author finds that the computation...

A lot of designated verifier signature (DVS) schemes have been proposed. However, all of them only provide the basic security requirement that only the designated verifier can check the validity of the signature. They are either not secure enough or lacking source hiding. Hence, in this article, we design a provably secure DVS scheme. It not only can attain the basic security requirement but al...

Universal Designated-Verifier Signatures (UDVS) are proposed to protect the privacy of a signature holder. Since UDVS schemes reduce to standard signatures when no verifier designation is performed, from the perspective of a signer, it is natural to ask if a UDVS can be constructed from widely used standardized-signatures so that the existing public key infrastructures for these schemes can be ...

Designated Confirmer signatures were introduced to limit the verification property inherent to digital signatures. In fact, the verification in these signatures is replaced by a confirmation/denial protocol between the designated confirmer and some verifier. An intuitive way to obtain such signatures consists in first generating a digital signature on the message to be signed, then encrypting t...

Most public key cryptosystems have been constructed based on abelian groups up to now. We propose a new public key cryptosystem built on finite non abelian groups in this paper. It is convertible to a scheme in which the encryption and decryption are much faster than other well-known public key cryptosystems, even without no message expansion. Furthermore a signature scheme can be easily derive...

An attribute-based signature with respect to a signing policy, chosen ad-hoc by the signer, convinces the verifier that the signer holds a subset of attributes satisfying that signing policy. Ideally, the verifier must obtain no other information about the identity of the signer or the attributes he holds. This primitive has many applications in real scenarios requiring both authentication and ...

In this paper, we propose a strong designated verifier proof signature scheme for an ad-hoc group and discuss its security properties. The proposed scheme provides a way that leaks authoritative secrets to only a designated person anonymously by one of the ad-hoc group members and no one knows that the secret is from a group member or the recipient, except the recipient. This group is called a ...

This work shows that the security improvement of Li et al. for Park and Lee’s nominative proxy signature scheme is still insecure against the original signer’s forgery. The problem within Li et al. scheme is that the verifier cannot judge the correctness of the parameter generated by the original signer from the received signature. Key-Words: digital signature, authentication, hash function, di...

Hwang and Cheng proposed the first strong designated-verifier ring signature scheme providing one-out-of-all signer anonymity to hide the actual signer’s identity. Their scheme also provides signer admission to admit who the actual signer is. However, the computation and communication costs caused by the signer admission are heavy because their scheme needs all ring members’ Schnorr promises. T...

In this study, a novel pairing based strong designated verifier signature scheme based on non-interactive zero knowledge proofs is proposed. The security of the proposal is presented by sequences of games without random oracles; furthermore, this scheme has a security proof for the property of privacy of the signer’s identity in comparison with the scheme proposed by Zhang et al. in 2007. In ad...